1. Field of the Invention
The invention relates to a rivet setting tool for setting blind rivet nuts, and a rotation reversal device.
2. Discussion of Relevant Art
Riveting tools for setting blind rivet nuts are known, which have a pressure medium rotary motor which, for first screwing a threaded rivet nut onto a threaded bolt of the apparatus, displaces the said bolt in right-hand rotation; and a separately operable pressure medium driven thrust device, which then in the course of the riveting process proper confers on the said bolt an axial motion for the upsetting process of the threaded rivet nut. After the end of the upsetting process, the pressure medium rotary motor is then driven so that the threaded bolt is displaced in left-hand rotation for unscrewing of the threaded nut. Such a blind rivet setting device can be gathered, for example, from German Patent DE-OS 37 01 883.
It is known from workshop practice that problems often arise in this and similar equipment in the transition from right-hand to left-hand rotation, the function of which is based on a complicated interplay between the pressure medium piston/cylinder drive, a rotation reversal device which is associated with the rotary motor, and a valve device which controls via an operating press button the supply of pressure medium to both the rotation reversal device and also the pressure medium piston/cylinder. Functional failures then appear particularly in that left-hand rotation is no longer possible, or on the contrary the pressure medium rotary motor can now be driven only in left-hand rotation.